The present invention is concerned with die apparatus employed to mechanically crimp metal electric terminals onto the end of an electric conductor.
Electric terminals with which the present invention is concerned are fixedly mounted on the end of an electric conductor to facilitate the convenient making of a secure mechanical and electrical connection of the conductor to another element of an electric circuit. While the terminals themselves are formed in a wide variety of sizes and shapes depending upon the specific application, the typical terminal, prior to attachment to the conductor, is formed with a conductor engaging portion of generally U-shaped configuration. The conductor is seated in the U-shaped portion of the terminal and the projecting legs of the U-shaped portion are then bent inwardly or crimped to surround and tightly grip the conductor.
Where relatively high volume production runs are required, the crimping operation is performed by a die assembly, and in order to achieve a reasonable production rate, it is necessary to provide a means for feeding the individual terminals to the die in an orderly manner. One such arrangement for so feeding the terminals is disclosed in U.S. Pat. No. 3,977,587. In the method disclosed in that patent, the individual terminals are integrally attached at one end to uniformly spaced locations along a carrier strip and the strip is advanced in step-by-step movement to the die by structure disclosed in U.S. Pat. No. 3,977,587. The die is provided with a cutter or severing device which will sever the terminal at the die as the terminal is being crimped onto the conductor.
The nature of the feeding device disclosed in my U.S. Pat. No. 3,977,587 is such that the feeding device is disengaged from the strip at a location spaced from the die and location of the terminal to be crimped. The location of the terminal longitudinally of the conductor on which it is to be mounted and also to the plane in which the shearing action which severs the terminal from the carrier strip is thus not firmly controlled by the feeding device. It is desired to shear the terminal from the strip at the end of the end-most U-shaped portion of the terminal and the terminal is thus connected to the strip by a relatively short neck portion extending from the end of the end-most U-shaped portion to the adjacent edge of the carrier strip. If this neck is not accurately located so that the shearing plane of the cover passes through the neck, obvious problems will arise.
Further, the typical terminal includes two longitudinally spaced U-shaped portions, one, the endmost, being conformed to be crimped around the insulation of the electric conductor and the second being conformed to be crimped around the stripped bare end of the wire. Two different die formations are required for this purpose, and alignment of the terminal with respect to the insulation and bare wire crimping dies is essential.
A second problem frequently encountered arises due to the fact that in crimping the U-shaped portion around a conductor of circular transverse cross-section, it is conventional to cause the die to progressively bend the ends of the legs of the U-shaped portions inwardly toward each other until the ends of the legs are bent inwardly from a trully circular configuration. This requires the die to have a downwardly projecting pointed central portion which, at the completion of the crimping operation is wedged between the two now reversely bent ends of the terminal legs.
As a result, difficulty is frequently encountered in disengaging the crimped terminal from the die.
The present invention is especially directed to improvements concerned with the accurate location of the terminal at the crimping station to the crimping dies and cutter mechanism and also the provision of a means for stripping the freshly crimped terminal from the die at the conclusion of the crimping operation.